The built-in "marriage penalty" in both House and Senate healthcare bills has received scant attention. But for scores of low-income and middle-income couples, it could mean a hike of $2,000 or more in annual insurance premiums the moment they say "I do."

The disparity comes about in part because subsidies for purchasing health insurance under the plan from congressional Democrats are pegged to federal poverty guidelines. That has the effect of limiting subsidies for married couples with a combined income, compared to if the individuals are single.

Of course, low and middle income folks are exactly who the new law is designed to help, so defenders will say it's obviously a reasonable trade off.